WHAT IS AVASTIN?
Eye doctors use Avastin to treat several eye and retina diseases, like age-related macular degeneration (AMD). AMD is the leading cause of blindness in people over 50 years of age in the United States. AMD is caused by the breakdown of the central portion of the retina, called the macula (the highly sensitive part of your eye that works like the film in a camera).Avastin also treats diabetic macular edema and central retinal vein occlusion (CRVO).
The macula is responsible for the detailed central vision in the eye. The macula enables us to see fine print, recognize faces and drive our car. There are two types of macular degeneration: dry and wet.In the wet form of macular degeneration, abnormal blood vessels grow in the back of the eye. Sometimes these vessels leak blood or fluid. This leakage causes blurred or distorted vision. Without treatment, vision loss can be quick and severe.
There are other eye conditions that cause loss of vision due to abnormal growth of blood vessels in the back of the eye. These eye diseases can even occur in young patients. They include conditions such as high myopia (nearsightedness), histoplasmosis, angioid streaks, and eye injury. Without treatment of this leaking, vision loss can occur.
Chronic macular edema, or swelling around the macula, is a condition that affects vision but does not respond well to the usual treatment drugs, like eye steroids. It can occur with conditions such as central retinal vein occlusion and diabetic retinopathy. Without effective treatment, vision loss could get worse or become permanent.
WHAT IS AVASTIN OFF-LABEL USE?
Avastin was not initially developed to treat eye conditions. Based upon the results of clinical trials demonstrating its safety and effectiveness, Avastin was approved as a chemotherapy drug by the U.S. Food and Drug Administration (FDA) for the treatment of metastatic colorectal cancer. As a condition of approval, the manufacturer produced a “label” explaining the indications, risks, and benefits. The label explains that Avastin works by blocking a substance known as vascular endothelial growth factor or VEGF. Blocking or slowing VEGF helps prevent further growth of the blood vessels that the cancer needs to continue growing.
Once the FDA approves a device or medication, physicians may use it “off-label” for other purposes. Ophthalmologists are using Avastin “off-label” to treat AMD and similar conditions because research indicates that VEGF is one of the causes for the growth of the abnormal vessels that cause these conditions. Avastin also treats macular edema in diabetic patients.
POSSIBLE AVASTIN LIMITATIONS
The goal of Avastin treatment is to prevent further loss of vision. Although some patients regain vision, the medication may not restore vision that was already lost. Avastin may not ultimately prevent further loss of vision from the eye disease.
HOW IS AVASTIN EYE INJECTION DONE?
After the doctor dilates the pupil and numbs the eye with anesthesia, he injects the medication into the vitreous — the jelly-like substance in the back chamber of the eye. Your doctor may continue to use Avastin injection into your eye as needed at regular intervals (about every four to six weeks). Your ophthalmologist will tell you how often you will need to receive the injection, and for how long.
You do not have to receive treatment for your condition but without treatment, these diseases can lead to further vision loss and blindness, sometimes very quickly. Other forms of treatment are available. At present, there are several other FDA-approved treatments for wet age-related macular degeneration: photodynamic therapy and injection into the eye of other VEGF inhibitors drugs called Eylea, Macugen and Lucentis.